(亦作d)
(pl. Ds或D's)
1
- the fourth letter of the alphabet英语字母表中第四个字母。
1.1
- denoting the fourth in a set of items, categories, sizes, etc.丁, D项, D类, D号（一组项目、分类或尺码的第四位）。
1.2
- the fourth-highest category of academic mark（学业成绩）D等, 丁等。
1.3
d
Chess denoting the fourth file from the left, as viewed from White's side of the board【棋】（从执白方左边数过来的）第四列。
1.4
- denoting the second-lowest-earning socioeconomic category for marketing purposes, including semi-skilled and unskilled personnel（为市场营销而划分的社会经济类别中的）较低收入群体。
2
D
（亦作dee）a shape like that of a capital D.D字形：in combination the D-shaped handle.D形把手。
2.1
- a loop or ring of this shape.D型圈（或环）。
2.2
D
a semicircle marked on a billiard table in the baulk area, with its diameter part of the baulk line, within which a player must place the cue ball when breaking off or restarting from hand（台球）开球区D字形区域。
3
- （一般作D）Music the second note of the diatonic scale of C major【乐】D音, D调（C大调音阶的第二音）。
3.1
- a key based on a scale with D as its keynote.D音键。
4
- the Roman numeral for 500（罗马数字）五百。
- [ORIGIN: understood as half of CIC., an earlier form of M （= 1,000）]
1.1
- (in the US) Democrat or Democratic.（美国）同Democrat或Democratic.
1.2
- depth (in the sense of the dimension of an object from front to back).同DEPTH（指厚度）。
1.3
- Chemistry dextrorotatory.【化】同DEXTROROTATORY:
D-glucose.
右旋糖; 葡萄糖。
1.4
- (with a numeral) dimension(s) or dimensional.与数字连用同DIMENSION, dimensions或dimensional:
a 3-D model.
三维模型。
1.5
- (in tables of sports results) drawn（比赛结果列表用语）平局。
1.6
- (on an automatic gear shift) drive.同DRIVE（自动变速杆上）。
1.7
- Germany (international vehicle registration).（国际车辆注册用语）同GERMANY.
- ORIGIN: from German Deutschland.